Year PPP $ per kg of oil equivalent 2000 5.987614268901466 2001 6.378647624804297 2002 6.546058691726825 2003 6.530768361323453 2004 6.436556726208523 2005 7.049375744807133 2006 7.506130086163551 2007 7.600260068892195 2008 7.970689283358149 2009 7.713232238218002 2010 7.853031570890607 2011 9.445933547261314 2012 9.104208988840607 2013 7.347869079143412 2014 7.731696586585098